Late blight found in PA
June 20, 2012 —
PENNSYLVANIA — Late blight has been found in at least four Pennsylvania counties, mainly on potatoes and tomatoes. Area growers are encouraged to scout their fields/high tunnels/backyard gardens for possible late blight problems.
Late blight symptoms can develop on leaves, branches, stems and both green and ripe vegetables. On leaves, pale green to brown spots appear on the upper surfaces. Some of the leaf margins can be pale green or water soaked. The spots may enlarge rapidly until entire leaflets are killed. In moist conditions, a downy white growth usually develops near the margins of leaf spots on the undersides of leaves. This “growth contains the spores that are easily blown around by the wind. Plants affected by “late blight” usually dry-up and collapse and die.
Organic growers can use some type of copper-based fungicide to protect their crops. Area vegetable growers that suspect a problem with late blight should bring a sample to their extension office for positive identification.